T here are cases, however, where these two forms are not interchangeable in that the present perfective progressive has also the meanings of continuousness, temporariness and incompleteness .

但是，由于现在完成进行体还带有进行体的持续性、暂时性和未完成性的含义，有时就不可以与现在完成体互换使用。比较。

youdao

The main causes are that the decrease of testicular function with aging is of a progressive course without a cut-point, and the serum level of T in the aging male has markedly individual variation.

主要原因是男子的睾丸功能与女性的卵巢不同，没有一个明确的终止界限，同时，健康老年男子的血浆T水平有较大的个体差异。

youdao

If we make--If we solve the problem of boredom setting in with progressive memory loss and radical personality changes, maybe boredom won't set in, but it's not anything that I especially want for myself.

如果用持续失忆,和剧烈人格变化来解决无聊的问题，也许不会产生无聊，但那不是我特别想做的事。

耶鲁公开课 - 死亡课程节选

Vanessa Sproul, a student from North Carolina studying history in Rome said the pick wasn't progressive enough and didn't represent a "bold" move.

WSJ: Dancing, Chants Greet New Pontiff

"There's no question that it's inconsistent with what is happening in Europe and on domestic routes in the UK that there shouldn't be progressive liberalisation on services on the North Atlantic, " he said.

BBC: 'Open skies' talks resume

President Obama learned a political lesson from President Clinton, which is that the tough decisions made in 1993 didn't advance the progressive cause.

FORBES: Grand New Party